This is handled by iBatis through implementation of Session.
http://ibatis.apache.org/docs/dotnet/datamapper/ch04s04.html#id401597
Every time you call BeginTransaction, iBatis use the logic below to
handle session:
public IDalSession BeginTransaction()
{
if (this._sessionHolder.LocalSession != null)
{
throw new DataMapperException ...snip...
}
SqlMapSession session = new SqlMapSession(this);
this._sessionHolder.Store(session);
session.BeginTransaction();
return session;
}
Session Store is done through this logic:
public static ISessionStore GetSessionStore(string sqlMapperId)
{
if (HttpContext.Current == null)
{
return new CallContextSessionStore(sqlMapperId);
}
return new WebSessionStore(sqlMapperId);
}
Details:
CallContext :
http://msdn2.microsoft.com/en-us/library/system.runtime.remoting.messagi
ng.callcontext(vs.71).aspx
WebSession: uses HttpContext which is unique to http requests.
----------------------
Web is usually automatically handle for each users. But if you are
doing multi-user in non-web with the same call context then you may have
to consider implementing your on thread safety session store. But
otherwise, session handles transaction automatically.
Example of your question:
try
{
sqlMap.BeginTransaction();
Item item = (Item) sqlMap.QueryForObject("getItem", itemId);
item.Description = newDescription;
sqlMap.Update("updateItem", item);
someObjectDAO.Save() // problem here
sqlMap.CommitTransaction();
}
catch {
sqlMap.RollBackTransaction();
}
-----------------
You will have to handle someObjectDAO.Save() in another session if you
don't have it to participate in the same session.
Something like someObjectDAO
public void Save()
{
SqlMapSession session = new SqlMapSession(sqlMap);
try {
session.BeginTransaction();
// do saving stuff here ...snip...
session.CommitTransaction();
} catch {
session.RollBackTransaction();
}
}
Regards,
Tom Nguyen
Sr. Developer
[EMAIL PROTECTED]
-----Original Message-----
From: Mike Hill [mailto:[EMAIL PROTECTED]
Sent: Friday, May 11, 2007 10:48 AM
To: [email protected]
Subject: Transaction question
Hello,
I'm new to iBatis .NET and had a quick question about how the
session/transaction stuff should work. The documentation examples shows
something like this:
try
{
sqlMap.BeginTransaction();
Item item = (Item) sqlMap.QueryForObject("getItem", itemId);
item.Description = newDescription;
sqlMap.Update("updateItem", item);
sqlMap.CommitTransaction();
}
catch {
sqlMap.RollBackTransaction();
}
Which works fine in this simple case where all of the transaction logic
exists in the data layer. In my case, I have several different Data
Access Objects I've created (roughly one for each of my entity objects),
and from my business logic layer I want to call several methods across
the different DAOs and have them all participate in a transaction. Can
someone guide me in the right direction?
All the DAO classes extend from a common base DAO which can easily
begin/rollback/commit a transaction by getting an instance of the
ISqlMapper and calling the appropriate methods. However since the
mapper is a singleton, and a transaction has been started, wouldn't this
then cause other DAO methods which may be called to inadvertently
participate in the transaction since each DAO would be using the same
ISqlMapper instance?
Thanks,
Mike
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